1. Field of the Invention
The present invention relates to filter pads with a pocket useful for filtering and removing contaminants and toxins from fluids. In addition, the present invention is directed to methods for removing contaminants and toxins from fluids using the filter pad with pocket.
2. Description of the Prior Art
It is known in the biological arts that ammonia and other fluid toxins and solid waste materials are excreted by animals as a result of normal animal metabolism. In addition, in substantially enclosed ecosystems, such as an aquarium, particulate matter or detritus from excreted solids or decayed solids accumulate, requiring removal to maintain a balanced, safe and relatively odor free ecosystem. Conventional methods for removing or neutralizing ammonia and other fluid toxins, odor causing chemicals, such as hydrogen sulfide, and various organic chemicals, as well as removing particulate waste material, include the use of zeolite and/or activated carbon in the form of loose chips, granules or a powder through which a fluid must pass. Such methods, however, are generally inconvenient and inefficient because the proper amount of zeolite and/or activated carbon must be measured and added to a filter container. The zeolite and/or activated carbon chips, granules or powder is messy to handle and also difficult to remove from the filter because the filter must be disassembled and cleaned prior to refilling with new zeolite and/or activated carbon.
Conventional methods for removing particulate waste material include the use of filters comprising a loose fibrous material typically packed into a filter container. However, such filtering techniques are inconvenient and inefficient because the loose fibers are difficult and messy to insert and remove and may be too loosely or too densely packed, thereby reducing filtering efficiency.
Several methods and apparatus have been developed to combine the filtering properties of certain materials, such as zeolite and activated carbon and the physical filtering properties of fibrous filter materials. Bags or pouches of fibrous filter material containing activated carbon on the like inside the bags or pouches have been on the market. Examples include the Whisper.RTM. Bio-Bag.RTM. sold by Willinger Bros., Inc., Wright Brothers Way, Oaklyn, N.J., and a filter product of Ginger Products Co., Toledo, Ohio. Both products are used in fish aquariums by placing the products in a filter assembly, such as an aquarium power filter, so that the aquarium water can pass through them.
The Bio-Bag.RTM. product comprises a fibrous filter material sewn together to form an open pouch in which activated carbon granules are disposed. The product is provided with a clip to close the open top for replacing the bag and its contents. However, the Bio-Bag.RTM. product is not structurally self-supporting and requires an internal frame to maintain its structural integrity in the filter assembly to facilitate fluid flow therethrough. This internal frame, which may be reused, increases the cost and complexity of the filter.
The Ginger Products filter also has an internal frame which is sealed to the external polymeric fiber material. Moreover, this product is sealed before it is sold, so the consumer or other user cannot conveniently add, remove or change the contents of the pouch.
The Ammo-Carb.TM. Hydro-Pouch.TM., manufactured and sold by the assignee of the present invention, comprises a sealed polymer mesh bag containing zeolite and activated carbon chips. However, the Hydro-Pouch.TM. polymer mesh bag does not filter solid waste particles and the pouch lacks structural integrity, thereby requiring insertion into a filter container in such a position to prevent the pouch from being dislodged when fluid is passed therethrough.
In addition, pads of filter material, such as nonwoven polymeric material of varying density in which the fibers are bound together to be substantially self-supporting, are also in use. Such pads have been impregnated with activated carbon and/or zeolite and used in various filtering environments, including aquariums, pet litter boxes and industrial filtering applications. For example, copending U.S. patent application Ser. No. 208,316 discloses a zeolite impregnated pad, which has use as a filter. U.S. Pat. No. 4,793,837 of Pontius discloses a filter pad impregnated with a combination of activated carbon and zeolite particles.
Such impregnated pads are unitary structures without pockets. Thus, the prior art impregnated pads are not particularly useful where it is desired to use filtering materials other than or in addition to the impregnated material, such as zeolite and/or activated carbon, or where no chemical filtering material, such as zeolite and/or activated carbon is desired.
In view of the deficiencies and inefficiencies of the prior art, it would be desirable to have a filter pad with a pocket in which a filter material may be disposed, which does not require a specially attached separate structure to maintain its shape during filtering use and which is relatively simple and inexpensive to manufacture and use